Announcing our first Lightning mainnet release, lnd 0.4-beta!

15 Mar 2018
on Announcement

Today, we at Lightning Labs are announcing the release of lnd 0.4-beta!
This release marks the 4th major release of lnd and the first Lightning
mainnet beta, an important milestone. With this release, lnd has gained a
considerable feature set, deeper cross-implementation compatibility, a new
specialized wallet seed, comprehensive fault-tolerance logic, a multitude of
bug fixes, and much more! This release is also the first release of lnd that
has the option to run on Bitcoin’s mainnet, with the safety, security,
and reliability features necessary for real-world, real money usage.

Note that this release is intended for developers of future Lightning
applications (Lapps) along with technical users and prospective routing node
operators. In this early phase of Lightning, we’re focused on providing the
software infrastructure (such as lnd!) necessary to bootstrap the network and
serve as a platform for future applications, services, and businesses. As this
is the first mainnet release of lnd, we recommend that users experiment with
only small amounts (#craefulgang #craefulgang #craefulgang)!

The maintainers of lnd would like to thank all the dedicated testers and
60+ contributors who helped make this release possible! We believe
that lnd 0.4-beta is a big step in the development of the Lightning Network and
will help make Bitcoin and other cryptocurrencies simpler, faster, safer, and
more ubiquitous.

A few of the highlights (more detail can be found in the release notes):

bitcoind support - previous versions of lnd required the use of btcd.
Now, users who prefer to run lnd with bitcoind can do so using the
instructions here.

New seed format, deterministic keys - a new and improved key creation and
recovery system makes it much easier to backup lnd nodes and also makes
recovery from data loss or corruption simpler and more reliable. These
improvements are also necessary for remote backup services, which will
provide additional safety for Lightning users.

Vastly improved fault-tolerance - safety and security of user funds is of
the utmost importance, and a great deal of effort has gone into making
lnd secure and stable in the event of power failures, network failures,
hardware failures, or other unexpected or adversarial conditions. Ensuring
that necessary recovery information is stored at all times and can be
correctly reloaded upon restart and reconnection to the Lightning Network
has been a major undertaking for 0.4-beta.

Automated Contract Resolution - sweeping funds back into a user’s wallet is
now handled by a concert of subsystems that together decide how and when
to spend all output types generated by an operating channel. Making this
process automated, fault-tolerant, and intelligent has demanded an immense
amount of effort, but is critical to the safety of funds managed by lnd. As
an aside, you’ll be happy to know that lnd batches transactions wherever
possible ;)

Segwit only - lnd has removed support for now-obsolete P2PKH
addresses, favoring both native Segwit and P2SH. As a result, all
transactions, even regular on-chain transactions, will benefit from lower
fees and will be healthier for the network.

Routing node metrics - lnd now provides tools to track fees and
payments at high volume, which is of particular interest to those operating
transaction routing nodes. Tools such as these can be used to optimize
revenue, throughput and reliability. Let the gamification begin!

NOTE: This release of lnd contains several breaking changes. In other
words, any previous lnd mainnet installations are not compatible with the
beta. As a result, users will need to upgrade using a completely fresh
installation or remove their existing channel.db database file before
upgrading. As a courtesy, we recommend that users close out any existing
channels (cooperatively if the peer is online, or force close otherwise) before
upgrading. A new utility command in the command-line interface, lncli
closeallchannels has been added to streamline this process.

Beyond Beta

lnd-0.4 beta is a huge accomplishment by many engineers, testers, and users
around the world, but it’s the very beginning for the Lightning Network. As
users begin to experiment with Lightning and as the network begins to grow,
we’ll be working on a number of key infrastructure components that will
contribute to the instant, user-friendly experience Lightning can bring to
Bitcoin and other cryptocurrencies.

Watchtowers and backups - to provide maximum safety for the funds of
Lightning users, “watchtowers” will monitor the blockchain for invalid
channel transactions. Typically, Lightning nodes need to be online in
order to protect against these events, but watchtowers provide this
protection for nodes that have intermittent connectivity, e.g. mobile
phones. Even for connected nodes, watchtowers can serve as a secondary
line of defense in the face of unplanned service outages.

Atomic Multipath Payments (AMP) - allow large Lightning transactions
to be divided into a series of smaller transactions as they’re sent over
the Lightning Network, but in such a way that they’re automatically joined
back together. The user sees only the total amount of the transaction,
without needing to be aware that AMP is being used behind the scenes. AMPs
also ease the mental burden of using channels, allowing a user to
interpret their balance readily as the sum of balances in channels. This
is made possible by the ability to send and receive an AMP-like payment
over multiple channels, at both source or sink.

Desktop and mobile apps - lnd-0.4 beta is targeted at technical
users, but we believe Lightning Apps that are simple and intuitive for
non-technical users will be essential to the growth of the network. To
that end, we’ll be updating our alpha Lightning
App to be compatible with
lnd-0.4 beta over the coming weeks, and will follow with mobile versions
as well.

Routing node tools and guides - more advanced Lightning users may want
to support the network while earning fees with their bitcoin by running
routing nodes. New tools and additions to lnd will help routing node
operators optimize revenue, maximize uptime, and manage capital. A robust
routing network is essential to the speed and privacy of Lightning, and
we’ll be working with the community to facilitate the growth of the
network..

Next-generation Autopilot and Mission Control - currently, lnd uses
relatively simple heuristics for Autopilot (peer finding) and Mission
Control (routing). These will be further optimized to provide a more
reliable, faster user experience.

Cross-chain atomic swaps - cross-chain swaps enable instant, trustless exchange of
assets residing on separate blockchains such as Bitcoin and Litecoin,
without the systemic risk introduced by custodial exchanges. Lightning
will enable more liquid exchanges, and cross-chain swaps will be a key
component for decentralized exchange infrastructures.